Cheapening Body Panels??

We parked our 2012 GL450 nearly anywhere without worrying about dents. The running boards stuck out enough to stop the other guys car door from slamming ours BUT even if it did, the panels felt twice as tough as our 2015's. Something has clearly changed in the composition of the "sheet-metal" if thats even what it still is.. not to mention the running boards hug the car tighter thus offering less protection. Came out into the parking lot yesterday to find our first "ding." After tapping the side panels .. its no wonder! I could easily make a dent in this thing with little pressure! Has anyone else noticed the apparent cheapening of the body panels? Does anyone have any information on it? One of the main reasons I liked these cars was the paint and body panel quality.